The Greening the Capitol initiative was launched in March, 2007 with the threefold goals of making the U.S. House of Representatives: 1) carbon neutral within 18 months, 2) reducing energy use by 50% in ten years, and 3) becoming a model of sustainable operations. We report on the recommendations to meet these goals, looking at the targets of opportunity at the Capitol Power Plant, the existing buildings, and the overall operations of the complex. Our findings have shown that these goals are achievable, and that through an integrated approach the savings in carbon and energy can be met. Specific examples include the lighting retrofits in the House offices, parking areas, and the Capitol dome; the retrofits to the HVAC systems and controls, including duct sealing, improving the efficiency of the energy and water use in the food service areas; and improved operations of the steam and chilled water distribution system. A key aspect has been better tracking and feedback to the building operators of the actual energy consumption. We report on the technical opportunities presented by these historic and symbolic buildings in becoming models of sustainability.